Slice for paper machines



April 5, 15927'. '1,623,096

D. B. DAVIES ET AL SLICE FOR PAPER MACHINES Filed 00th 24, 1925 Patented Apr. 5, 1927.

UNITED STATES l 1,623,096 PATENT oFFicE.

DAVID B. Davies AND COMMADORE J. 'it-noms, or GREEN BAY, WISCONSIN.

SLICE FOR PAPER I'ECHINES.

Application led October 24, 1925. Serial No. 64,565.

This invention relates to a slice for a paper machine and more particularly to a slice adapted for alternateiy varying at freuently spaced intervals the depth of stock owing thereunder.

The ordinary paper machine slice consists usually of a metal strip with a straight edge on its lower side. This slice regulates the thickness of the sheet of stock coming onto the wire. When a sheet of paper is formed in the ordinary way with this type of slice', the tendency of the fibers is to run lengthwise-with the stream of stock in the machine direction. Because of this fact a sheet of paper is formed which is strong 'with the machine direction but comparatively weak across the sheet. Furthermore the ordinary slice has only a general vertical adjustment but no local adjustment'at f frequent intervals along its length. In order to correct the inequality in the strength of the sheet of paper with and across the machine direction, as well as to correct the tendency which the fibers have `to settle out in the flow box and behind the slice, various expedients have been tried, including the use4 "of baffles formed ofslotted strips or spaced fingers -dipping into the stock. A This invention has for one of its objects to accomplish that which` the aforementioned 'expedients have tried unsuccessfully to do 'and to effect the formation ofa sheet of paper having considerably greater strength across the machine' direction than hitherto. It is a further object of this invention to provide locally adjustable means for alternately varying at 'frequent intervals the depth of stockflowing beneath the slice.

,lt vis a further :object of this invention to.

provide a slice adapted to cause the fibers in the stoclr flowing beneath the slice to crisscross in theirv flow and thus to form, a stifonger'sheet of paper of better formation.

`It is u. further object of this invention to p'rovide a slice having means for varying the height of`stock flowing thereunder at frequentintervals' along its length and flexible means associated withsaid slicefor levelling the flow of-'s'toclr` and removing the foam and air bubbles formed on ,the surface thereof.. f i

Other and yfurther important objects of this invention will be apparent from the disclosures in .the specification and the accompanyingdrawings.Y v This invention (in a preferred form) is -chineg Figure 2 is a longitudinal section showing a portion of a paperv machine with our slice in operation;

Figure 3 is an enlarged Section takeno'n line III-III of Figure 1 showing parts in elevation;

Figure 4 is an enlarged fragmentary section. taken on line IV-"-IV of Figure 1, and

Figure 5 is a perspective view showing the operation of the slice.'

As shown on the drawings:

The reference numeral 1 indicates a slice embodying the principles of this invention. Said slice is preferably formed of a sheet of metal of suitable thickness and is provided at its ends with flanged extensions 2. Adjusting screws 3 extend through suitable brackets 4 secured to portions 5 of the paper machine'frame and through said flanged extensions 2 to provide means for raising and lowering the slice 1. Said slice 1 is provided along its lower edge with spaced recesses or orifices 6, substantially semicircular in form.` Between each of said recesses 6 there is`thus formed a straight edged portion 7.

The slice 1 is shown in Figure 2 in normal spaced position above an apron 8 serving as a dem to hold a predetermined head of stock 9 over the vapron 8. The-stock--as is well known-flows under theflowei'f edge of the slice ontoa travelling, 'endless wire 10 which passes around a breast roll 311, table rolls 12 andwire rolls 13. Asthis stock flows over'the wire'10 andthe table rolls 12, the water is gradually drained through the wire leaving'a web of paperforined thereon. In our v'inveiitiom'b'eclai'isefof the recessed lower edge' of the slie'1,' thestock flows under the slice in spaced lfas shown in Figure'` 5. A certain a: f un`t`i`f the stock also flows under 'thestri t edges 7 in level portionsl 15. 'Thef'ds which the'ridgesof'stook 14'wl over the wire willlobvouslydpend upon the speed of the' wire'jand' the hea'd of stock behindn the' slice. vVlith'a :wire travelling aft ordinary speeds, the"` rfid e`s114` vei'rtei'id vto 'a considerable distance' 'be ore 'flattening v"out AVAILABLE CC and during, this distance adjacent ridges 14 cross, as' ati 16, and alternate rldges recross,

^ as at 17. In so doing, the individual-fibers apron and under the slice tends to settle the fibers tothe lower side and to permit the fibers to run lengthwise. Inour 'improved slice there is sufficient turbulence-set up to an uneven sheet.

prevent the fibers from settling but the turbulence does not resultA in the formation of The currents formed in this flow 'of stock causethe stock to travel further down the wire before suiicient water is extracted to set the fibers. This is a 25 very desirable feature in paper making.

While the s lice as above described.operates satisfactorily, We have found that its operation maylbe further improved by providing means for locally adjusting the height ofthe recesses or orilices 6 across the length ofthe slice. Suitable means for this purpose comprise gates 18 slidably secured by' means of flanged strips 19 on the back side of the slice.' Each gate18 is here shown as controlling two ofthe adjacent orifices 6 but it is obvious that-wider gates may be used if desired. The gates 18 and the slice l are provided at theirupper edges with rearwardly extendinganged portions 20 and 21, respectively, through which extend vertical adjusting bolts 22'. By means of said bolts 22,each gate 18 may be individu ally raised or'loweredto vary the depth of stock passing through the orifices 6 which said gate controls. The lower edge of each gate 18 is preferably formed with spaced recesses 23' corresponding to the recesses 6 but of lower maximum height. The purpose ot' the adjustable gates is to vary the depth of stock passing through the orifices 6 and thus. to control the thickness of the sheet j at all points across its width. v As the stock flows beneath the s'lice 1, un-

der certain conditions,- more or less foam is formed. In order to prevent this4 foam from carrying along onto the wire and marring the formation of the sheet and also to com lete the. flattening out of the ridges 14, we ave provided a device comprising a flexible strip 24, preferably .formed of fabric material and supported transversely of the wire by'means of the support or bar 25. Said strip 24 is" positioned at a suitable oint in front of the slice J1 and is so ad- )usted vertically that its lower edge 26 just drags on the surface ofthe stock. Thefoam formed on the surface of the stock behind the strip 24 is either dissipated by contact with said strip or else is retained by it and thus prevented from passing' along with the stock. The levelling effect of thev strip 24 results in the formation of a more uniform sheet of paper but said device is not an essential part of our invention, since the slice will perform very satisfactorily alone.

We are'aware that many changes may be made, and numerous details of construction may be. varied through a wide range'witnout departing from the principles of this invention, -and we therefore do not purpose limiting the patent granted hereon. ornerwise than necessitated by the prior art.

Te claim as our invention: A1. A slice for paper machines having unobstructed orifices-.along its lower edge whereby streams ofstock of unequal depth are allowed to iow thereunder onto the wire in the direction of said wire. y

2.A slice for paper machines having spaced, arc-shaped notches along its lower edge whereby-streams of stock of unequal depth are allowed to flow thereunder, and means associated with said slicefor separately adjusting the height of groups of said'notches. 3 y Y 3. A slice 'for paper machines having spaced, arc-shaped notches along its lower edge whereby streams of stock of unequal depth are allowed to flow simultaneousxy thereunder, and means associated with said slice for separately adjusting the height of said notches at frequent points along lthe length of said slice.

4, In combination with a paper machine, including the apron and wire thereof, a slice associated with said apron to regulate the flow of stoek, means on said slice for'alternately varying the depth of said flow at fre- -quently spaced intervals along the length of said slice and tiexible means positioned farther along the wire'adapted to lic against the surface of said stock.

' 5. A slice for'Fonrdrilnier paper'machines having spaced substantially seinicircular orifices along its bottom edge.

6, In a Fourdrinier-pap'er 'inacline, the combination with an apronl,`o f,a' slice. having spaced apart notches in its'bottom edge. the height of said bottom edge from said apron being such that alternate level and raised streams of stock arel caused to How under said slice in the,direction of the wire,

'the raisedl streams being allowed to criss cross 1n 4their` How on the wire and to flattenv out naturally.

In testimony whereof we have hereunto subscribed our names.

DAVID B. DAVI'ES. COMMADORE J. THOMAS.

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